R56.00 Simple febrile convulsions

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Febrile convulsion NOS
• Febrile seizure NOS

Applies from R56 Convulsions, not elsewhere classified

Excludes1 (never code together)

• dissociative convulsions and seizures (F44.5)
• epileptic convulsions and seizures (G40.-)
• newborn convulsions and seizures (P90)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 201 — Seizure Disorders and Convulsions
• CMS-HCC V22: HCC 79 — Seizure Disorders and Convulsions
• ESRD V24: HCC 79

MS-DRG index

Defines the logic of DRG(s) 100-101 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 780.31 Febrile convulsions (simple), unspecified

Code annotations containing back-references to R56.00

Back-references to R56.0

• Type 1 Excludes: R50 Fever of other and unknown origin ("febrile convulsions (R56.0-)")

Diagnosis Index entries for R56.00

• Convulsions (idiopathic) › febrile
• Convulsions (idiopathic) › febrile › simple
• Seizure (s) › febrile (simple)

Nearby codes

• R56 Convulsions, not elsewhere classified
• R56.0 Febrile convulsions
• R56.00 Simple febrile convulsions (this code)
• R56.01 Complex febrile convulsions
• R56.1 Post traumatic seizures
• R56.9 Unspecified convulsions